Electronic devices having touch panels as input means are prevalent. Screen scroll control is performed in these electronic devices.
Patent Literature 1 includes the following descriptions. When touch determination means has determined that a touch input whose shift speed or shift amount is in excess of a predetermined given value has been made in one certain direction on an object which is registered as exhibiting a virtual continuous extent outside a display screen, display control means provides a scroll display of the object in the direction while taking the shift speed of the touch input as initial speed. Patent Literature 1 also includes descriptions stating that, when the touch determination means detects completion of a touch input, the display control means performs display control to thereby slow scroll speed of the scroll display to a stop.
Patent Literature 2 includes descriptions about control that is carried out to take, as a displacement scroll state, a period during which coordinates are input by way of coordinate input means and switch the state to an inertial scroll state when the inputting of coordinates entered by way of the coordinate input means has stopped. In the displacement scroll state, control is performed in such a way that a display screen is scrolled along a vector which is equal to a vector of a change in input coordinates. In the meantime, in the inertial scroll state, control is performed so as to scroll a display screen along a vector proportional to a vector of changes in input coordinates achieved right before cessation of inputting of coordinates and decrease the scroll speed of the display screen decreases with a lapse of time.